Translational instrumentation for spondylolisthesis and scoliosis reduction

Abstract

An instrument for spinal procedures is a vertebral endplate spreader device having a vertebral endplate spreader and a driver handle. The vertebral endplate spreader includes a linkage with a drive sprocket operatively connected for rotation relative thereto and with a secondary sprocket. The secondary sprocket is operatively connected for rotation relative to the linkage. The vertebral endplate spreader includes a belt operatively connected to the drive sprocket and the secondary sprocket to be driven about a belt axis. The driver handle has a distal end and a proximal end. The distal end is operatively connected to the drive sprocket to actuate rotation of the belt.

What is claimed is: 
     
       1. A vertebral endplate spreader device comprising:
 a vertebral endplate spreader including:
 a linkage with a drive sprocket operatively connected for rotation relative thereto, and with a secondary sprocket operatively connected for rotation relative to the linkage; 
 a belt operatively connected to the drive sprocket and the secondary sprocket to be driven about a belt axis, wherein the secondary sprocket includes a constant diameter and is in direct abutment with the belt; and 
 
 a driver handle having a distal end and a proximal end, wherein the distal end is operatively connected to the drive sprocket to actuate rotation of the belt. 
 
     
     
       2. A vertebral endplate spreader device as recited in  claim 1 , wherein the drive sprocket and the secondary sprocket have different diameters to facilitate distraction between respective endplates of two vertebrae. 
     
     
       3. A vertebral endplate spreader device as recited in  claim 1 , wherein the diameter of the drive sprocket is larger than the diameter of the secondary sprocket. 
     
     
       4. A vertebral endplate spreader device as recited in  claim 1 , wherein the belt includes an outer textured surface to engage respective endplates of vertebrae for distraction and correction of vertebral alignment. 
     
     
       5. A vertebral endplate spreader device as recited in  claim 4 , wherein the outer textured surface includes teeth, wherein each tooth includes a respective point more proximate to a clockwise direction side of its respective tooth than a counter-clockwise side relative to a side of the drive sprocket from which the driver handle extends. 
     
     
       6. A vertebral endplate spreader device as recited in  claim 4 , wherein the outer textured surface includes teeth, wherein each tooth includes a respective point more proximate to a counter-clockwise side of its respective tooth than a clockwise side relative to a side of the drive sprocket from which the driver handle extends. 
     
     
       7. A vertebral endplate spreader device comprising:
 a vertebral endplate spreader including:
 a linkage with a drive sprocket operatively connected for rotation relative thereto, and with a secondary sprocket operatively connected for rotation relative to the linkage; 
 a belt operatively connected to the drive sprocket and the secondary sprocket to be driven about a belt axis; and 
 
 
       a driver handle having a distal end and a proximal end, wherein the distal end is operatively connected to the drive sprocket to actuate rotation of the belt, further comprising a gear transmission operatively connected between the drive sprocket and the distal end of the driver handle to reduce a required torque input through the driver handle. 
     
     
       8. A vertebral endplate spreader device comprising:
 a vertebral endplate spreader including:
 a linkage with a drive sprocket operatively connected for rotation relative thereto, and with a secondary sprocket operatively connected for rotation relative to the linkage; 
 a belt operatively connected to the drive sprocket and the secondary sprocket to be driven about a belt axis; and 
 
 a worm gear and worm shaft operatively connected to the drive sprocket to rotate the drive sprocket when driven by the worm shaft; and 
 a driver handle having a distal end and a proximal end, wherein the distal end is operatively connected to the drive sprocket to actuate rotation of the belt. 
 
     
     
       9. A vertebral endplate spreader device as recited in  claim 8 , wherein the worm shaft is a portion of the distal end of the driver handle. 
     
     
       10. A kit for performing spinal distraction and vertebral alignment, the kit comprising:
 a vertebral endplate spreader including:
 a linkage with a drive sprocket operatively connected for rotation relative thereto, and with a secondary sprocket operatively connected for rotation relative to the linkage; and 
 a belt operatively connected to the drive sprocket and the secondary sprocket to be driven about a belt axis, wherein the secondary sprocket includes a constant diameter and is in direct abutment with the belt; and 
 
 a driver handle; and 
 a plurality of implants of varying sizes. 
 
     
     
       11. A kit as recited in  claim 10 , further comprising additional vertebral endplate spreaders and additional driver handles of varying sizes. 
     
     
       12. A kit as recited in  claim 10 , further comprising bendable screws of varying sizes for use in one or more of the plurality of implants.